Telephone.



I A. G. KAUFMAN & L. J. LIPPMANN.

TELEPHONE.

APPLICATION FILED NOV. 13, 1906.

2 SHEETS-SHEET 1.

M w m m a P ATTORNEYS A. G. KAUFMAN & L. J. LIPPMANN.

v TELEPHONE. v I APPLICATION FILED- NOV. 13. 1906. 921,1 19.

Patented May 11, 1909.

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WITNESS 8 4J2 a ATTORNE Y8 hurrah snares PATENT enrich,

ADOLPH G. KAUl MAN AND LEOPOLD .T. LIPPMANN, OF NEW YORK, N. Y ASSIGNORS 'lO AlvllilRlOAN OALLAPHONE COMPANY, OF NEW YORK, N. Y., A CORPORATION OF G HORG lA TELEPHONE Application filed November 13; 1906. Serial No. 343,198.

specifization of Letters Patent.

Patented m y 1 1, 1909.

7 o (ill whom it may concern: Be it known that we, ADOLPH G. KAUF- MAN and LEoPoLn J. LIPP1s-1ANN,.,,bothciti-f zens of the United States, and residents of the borough of Manhattan, city, county, and State of New York, have jointly invented certain new and useful Improvements in "ielephones, of which the following a speci-.

; same sound simultaneously at different places; second, to provide anarrangement ywhich telephones of the usilal type maybe combined conveniently with our, l'o'udspeaking telephones; third, to provide proved means for giving'signale, pro aratory to speaking overthetelepho'ne, an fourth, to provide various 1m rovements 1n con struction, as will be in y described herein afteryand particularly pointed out in the appended claim.

Reference is to be had to the accompanying drawings, in which-+v a Figure 1 is a front elevation of a transmittee station constructed according to ourin vention; and Fig. 2 is a diagram'showingthe arrangement of circuits for the apparatuses.

We will first describe the construction of the transmitter station, partioularl with reference to Fig. 1. Upon a suitable ase or board A which is secured to the wall-plate B are 'set holders O- (five as shown) for' the preferabl screens (T toprevent t e entrance of dust and other foreign matter. )At the forward end'of each transmitter islocated a soundreceiving trumpet or tube D, D, the central trumpet I) being straight, while the lateral.

trumpets D are curved, so that they will converge forwardly. Adjacent to the point toward which thesaid sound-receiving tubes I converge, we locate a-guide K for positioning the operators mout so that the sound waves will producethe maximum effect.

. screw K This annular guide K is preferably adjustable, being for thispnrpose carried by a red K mountedteslide in -97 sleeve K and se-\ cured in po'sition after adjustment by a set We have found that with differentpersens the distance at which the ring K -should be from the sound-receiving tubes D,

' provided with D,in order to secure. the best-results, is not the same, hence we have made provision for per se. The'receiver (indicated diagram matically at M) may likewise be of'any approved construction, although we prefer a receiyer-provided with a curved. amplifying horn- R, and particularly the type disclosed in our ap lication for a patent filed February ,7, 190.7, ,erial No. 356,171. W

- The connectionsin which the transmitter and receiver, hereinbefore referred to, may be utilizd are shown in Fig. 2. A's' illus- 'trated in Fig. 2, wires 20, 20?, 2,0,20", 20

are connected with one terminal of each of the transmitters D, D, the other terminals are connected by wires 21, 21?, 21?, 21, 21 .with switches Y from which a wire 22 leads to one pole of a battery 23. Suitable fuses T are interposed in the-wires 2], 21 21*, 21, 21 between the res ective switches Y and the transmitters D, The wire 20 is connected with two receivers (in series), 25 being the wire connecting one receiver with the other, and wires 25, 24 complete the circuit by connection with the battery 23.

'From the wire 24 branch wires 25, 26, 27, 2S

and 29 each lead to one of the receivers, and then wires,25 26 27, 28 and 29 connect with another receiver which also has a connection to the wire 20, 20*, 20", 20 and 20 respectively. It will therefore be seen that eachof the transmitters D or D is in circuit With. a plurality of receivers, two of then. in

the particularzcs se illustrated. If, for instance, the switch Y, shown at the extremeleft in Fig. 2, is thrown in, the circuit will be closed through the two receivers which are shown connected by the wire 25. The entire current of the battery 23 will pass through the said receivers, and owing to this fact,- and also to the use of the amplifying horn R, the words spoken into thetransniitter will be heard very distinctly evcnat a considerable distance from the receivers (pan ticularly when employing the sensitive construction of both transmitter and receiver shown in our applications hereinbefore referred to) We therefore provide a very loud-speaking telephone, and the advantage of such an arrangement will be understood by reference to a few examples of use. For instance, in a shop while the employees are at work at their various benches or machines, any one of them can be called up and asked to report, say, at the ofiice, andthe signal will be heard by all employees who are within the room; or in a hotel a loud-speaking telephone of this character may be installed in the cafe, and the clerk may, from the central station, send a message such as Telegram for Mr.- Smith; or, Mr. Jones is wanted at the office, and so on. Alarms of fire may also be sent in the same way very expeditiously. By throwing in two or more of the switches Y, a greater number of transmitters and receivers will be included in the circuit. A multiple switch or the general switch; such as indicated by Z in Fig. 2, is provided which is so constructed that a number of switches or all of them may be operated simultaneously. When wishing to send an alarm of fire, the clerk in the hotel, for instance, would operate the general switch Z, and then shout his warning message into the transmitters, in which case the message would be heard in all the rooms in which loud-speaking receivers are installed.

We have shown the receivers in circuit with the transmitters directly, but we desire it to be understoodthat the indirect connection by means of induction coils, which is well-known in telephony, may be used in connection with our invention, and where in the claims we speak of elements of the apparatus being in circuit with each other, we desire it to be understood that this term is used in a sense broad enough to include an inductive relation,

In some cases it may be convenient to provide means whereby a telephonic answer may be given to the operator at thecentra]. In Fig. 2, a wire is so arranged as to lead part of the current of" the battery 23 to a transmitter X, located adjacent to one of the receivers, and the other terminal of said transmitter is connected by a wire 3] with a receiver U, from which a wire 32 leads to a switch lever V normally kept down by hanging the receiver U on it in the custon'iary manner. The circuit is broken in this position, but when the receiver U is removed from the hook, the lever V swings upward under the influence of a spring and closes the circuit at 38 through a wire 34 connected with one terminal of the battery 23. The receiverU and transmitter X are not of the loud speaking variety and use only part of the current of the battery.

We claim as our invention:

In a telephone system, the combination of a common source of current, a conductor leading from one ole to a plurality of line terminals, a plura ity of transmitter-circuits each having therein a transmitter, the transmitters being so grouped as to be simultaneously operated from the same source of sound, switches individual to the transmitter-circuits and capableof being operated singly or together, one or more receivers in and individual to each transmitter-circuit, and a common conductor leading from the other pole of-the battery or other source of current to the receiver-circuits.

In testimony whereof, we have signed our names to this specification in the presence of two subscribing witnesses.

ADOLPH G. KAUFMAN. LEOPOLD J. LIPPB IANN.

Witnesses JOHN Lorna, JQHN A. knHLENBncK. 

